High and low confining pressures have different effects on the deformational properties and mechanical index of frozen soil. Triaxial compression tests were carried out for frozen silty clay under three different temperatures and four confining pressures at different strain rates. The test results indicate that the stress-strain curves behave in the same form under different confining pressures and different strain rates at the same temperature of frozen soil; the triaxial shear strength has a linear relationship with confining pressure and temperature

and an exponential relationship with strain rate; the deformation modulus

independent of confining pressure

has a linear relationship with temperature

and an exponential relationship with strain rates. And then the deformational property is explained from the viewpoint of structural changes of frozen soil.